Add in LDFLAGS before looking for the serf library in case APR or APR-util need some dependencies.
Add in LDFLAGS before looking for the serf library in case APR or APR-util
need some dependencies.

* build/ac-macros/serf.m4
  (SVN_LIB_SERF): Add in pre-existing $LDFLAGS to our link check.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@865956 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,wbond/subversion,wbond/subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion